How do mobiles work?

Mobile phones work on the same principle as television and radio by using radio frequency (RF) fields to communicate information. The building blocks of a mobile phone network are base stations that transmit and receive calls. When a mobile phone connects to a network, it uses RF signals to communicate with the nearest base station. This is a two-way function, with base stations and handsets sending information to each other
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Click one of the handsets to see how RF signals travel across mobile and fixed-line networks.

The area covered by a base station is known as a cell. Each cell is usually split into three sectors, which overlap with the sectors of neighbouring cells to create an uninterrupted network. When people travel, the signal is passed from one base station to the next, and typically never has to travel further than the nearest base station.

The size and shape of each cell is determined by the features of the surrounding area, such as buildings, trees and hills, which can block signals. Cells are largest in flat open landscapes, where they can cover up to a five kilometre radius. Cells in urban areas cover up to a two kilometre radius. The smallest cells are in built up areas, where micro-cell base stations are used to provide extra coverage and capacity.

Click and drag the handset to see how the signal is passed from one base station to the next.